<template>
    <div>
        <router-link 
        tag="div" 
        to="/" 
        class="header-abs"
        v-show="showAbs"
        >
            <div class="iconfont bcak-icon header-abs-back">&#xe624;</div>
        </router-link>
        <div class="header-fixed" 
        v-show="!showAbs"
        :style="opacityStyle"
        >
            <router-link to='/'>
                <div class="iconfont header-fixed-back">&#xe624;</div>
            </router-link>
            景点详情
        </div>
    </div>
</template>
<script>
export default {
    name:'DetailHeader',
    data () {
        return{
            showAbs:true,
            opacityStyle:{
                opastyle:0
            }
        }
    },
    methods:{
        handleScroll () {
            const top = document.documentElement.scrollTop
            if(top > 60){
                let opacity = top / 140
                opacity = opacity > 1 ? 1: opacity
                this.opacityStyle = { opacity }
                this.showAbs=false
            } else {
                this.showAbs=true
            }
        }
    },
    activated () {
        window.addEventListener('scroll', this.handleScroll)
    },
    deactivated () {
        window.removeEventListener('scroll', this.handleScroll)
    }
}
</script>
<style lang='stylus' scoped>
 @import '~styles/varibles.styl'
.header-abs
    position absolute
    left .2rem
    top .2rem
    width .8rem
    height .8rem
    line-height .8rem
    border-radius .4rem
    text-align center
    background rgba(0,0,0,.8)
    .header-abs-back
        color #fff
        font-size .4rem 
.header-fixed
    z-index 2
    position fixed
    top 0
    left 0
    right 0
    line-height $headerHeight
    height $headerHeight
    text-align center
    color #fff
    background $bgColor
    font-size .32rem
.header-fixed-back
    position absolute
    top 0
    left 0
    width .64rem
    text-align center
    font-size .4rem
    color #fff
</style>
